I recall the days of navigators practising their astrological weirdness whilst I was on the Tin Triangle. Much muttering and consulting ancient tablets of tables and star charts at the planning stage; crystal balls, incense and pigeon entrails probably featured as well. Finally they would produce their plan and off we would go to the aircraft, with the navigators clutching their lodestones, quadrant staffs and other tools of their mysterious art. I just carried their sandwiches...
The more imaginative of the breed would use a 2 sextant method, which involved hopping (a challenge for our more cuddly nav radars) between port and starboard sextant. All we dumb co-pilots had to do was to count them down to the precise moment at which to start the clockwork, then advise them of the speed change through the 'shot'. With a bit of practice you soon learned which one of a series to cock up, reducing a 7 shot set to a mere 3...
After the athletics and clockwork were completed, various mysterious numbers would be chanted over the intercom, together with prayers to their gods of astrology. Much muttering, pencil chewing, scribbling and abacus work would then follow - and about 10 minutes later they would come to a vote and proudly announce "Turn one degree port"!
Actually, the good navigators were astonishingly accurate with astro, particularly if Doppler was available. I last encountered astro in 1979; when I came back to big aircraft after 4 years elsewhere I was amazed at how poor the young navs were at astro, compared to the V-force hairies. One day, or rather night, an ancient mariner nav instructor took the first tourist nav on our crew out to the jet at Akrotiri, to practise their black art of the occult. After about an hour, they returned to the bar to announce that we were, in fact, 500 nautical miles due east of Moscow...
However, a few pencil on beer mat calculations then followed, the error was resolved and off we all trooped to Chris'. Again!
I guess the sextants and all those mysterious books have long since disappeared, ever since GPS/LINS came upon the scene?
That said, one of the most important bits of kit on the SR 71 was an automatic astro tracker - and if it was good enough to navigate with that at Mach 3.5+......